search: tuning of hierarchical facet
search: tuning of hierarchical facet

Tested-by: Tibor Simko <c7116e45300b163846dc01f3ed02116e3f8ef7a5@cern.ch>
Signed-off-by: Jiri Kuncar <2bdffcb416fed3002465740d19a053a39918cbe5@cern.ch>

tiborsimko/invenio-search,inveniosoftware/invenio-search,tiborsimko/invenio-search,inveniosoftware/invenio-search